Brands don't matter. Owlnsr says Scott's WinterGuard is rich in fast release N, so it would be a good winterizer. Though it does have some K in it, so if you get extended periods of snow cover that may be an issue.

I am confused.

I should be looking for a fertilizer with fast release nitrogen?

Wouldn't that promote late season top growth?

I thought the goal was to have a quick spring green up and growth.

No, you want to apply it when grass naturally stops growing. At that point, photosynthesis is still going on but instead of using that energy for blade growth, the plant instead stores it as carbohydrates. It is those stored carbohydrates that help with spring green up.

thanks for the education.

do the fertilizer bags list fast and slow release nitrogen on them and what would be a good ratio?

Most bags will list the percentage of slow release N. The Scott's products do. For general purpose , 50-50 or close to is good. For winterizing, you want as little slow release as possible, hence the recommendation to use urea.

So to recap, you apply the winterizer after the grass stops growing but before it goes dormant from cold or frost. You want the roots alive but the top doing nothing.

Side note: My lawn has almost stopped growing. I have a couple of tufts still trying to get taller than the rest. Then again I'm not interested in early spring green up, so I don't winterize...which is why this is a side note.

Then again I'm not interested in early spring green up, so I don't winterize

Blasphemy!

You guys think Milorganite around Thanksgiving is good enough for that spring green-up? If my lawn is in good shape, should I really be concerned with throwing down Winterguard?

Milorgranite would be the last fertilizer I would use to winterize. Not only does it contain little nitrogen but its slow release

You guys think Milorganite around Thanksgiving is good enough for that spring green-up?

Milorganite is not a good winterizer since it's 60% organic.

If my lawn is in good shape, should I really be concerned with throwing down Winterguard?

There's benefits to winterizing. Early green-up in itself is one from a visual perspective, but early green-up leads to early photosynthesis which leads to deeper roots and more stored energy to make it through the summer. If you don't care about all that then no, you don't need to be concerned with winterizing.

The explanations for the theory behind winterizing given by dchall
and j4c11 are right on, but there are a lot of holes in it.
I've followed it for years and still do, but it is currently being
challenged based on results in on-going studies and I'm beginning to
re-evaluate.

I have a stand of 100% KBG, no fescue or rye except a couple of small areas in the North side lawn. in zone
5b. I've dropped as much as 5# of N and 2# of K between September and
November with no ill effects. On the other-hand, other than wishful
thinking, I can't say that I've seen any improvement the next year
either.The new theory and suggested rational does make sense.